The solid reaction of lithium hydride and lithium hydroxide in lithium hydride pellet under normal condition and the application of CO2 for long-time storage

Highlights: • The solid reaction of LiH and LiOH is first directly observed at normal ambient condition. • XPS analysis. • Using CO₂ as pre-treatment gas is helpful to prevent LiH from bubbling after long storage period. The solid reaction of lithium hydride and lithium hydroxide in lithium hydride pellet is first directly observed at normal ambient condition after 4 years storage. Layer-by-layer XPS results show that LiOH hydrolysis layer quickly forms on the LiH surface, LiOH reacts with bulk LiH to form Li₂O and H₂. Due to the great H₂ outgassing after long time conservation, bubbling problem actually exists during the practical long-time preserving period. Using CO₂ as pre-treatment gas during the LiH sample preparation process is a feasible way to prevent LiH sample from bubbling after long storage period. Moreover, Li₂CO₃ shows possible delay effect on the solid reaction of LiOH with LiH in this work, thus preserving LiH sample in CO₂ containing atmosphere might also be an prospective way to protect the sample from further corrosion.